The inventive filed relates generally to pulse width modulation circuits and methods for pulse width modulation. The inventive field also relates to reducing noise in pulse width modulation circuits and methods.
Pulse width modulation techniques and methods are well known and have a wide variety of applications. For example, a pulse width modulation circuit may be an integral part of a switcher.
One approach to pulse width modulation is to compare an analog signal to a fixed sawtooth signal, for example, by inputting the analog signal and the sawtooth signal into a comparator. FIG. 1 illustrates operation of a typical pulse width modulation circuit. As illustrated, an analog signal 2 and a sawtooth signal 4 are compared, which results in a square wave output 6. As well understood in the art, the value or amplitude of the analog signal 2 relative to the amplitude of the sawtooth signal 4 will determine a pulse width P of the square wave output 6.